Which company owns MAC address prefix 4C:8F:A5?

MAC address prefix 4C:8F:A5 is registered to Jastec in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 4C:8F:A5 has a network interface built by Jastec.

What is the OUI 4C:8F:A5?

4C:8F:A5 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Jastec. It covers every address from 4C:8F:A5:00:00:00 to 4C:8F:A5:FF:FF:FF, or 16,777,216 addresses in total. It is also written 4C-8F-A5.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 4C:8F:A5:00:00:00 that is 4C:8F:A5 — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.

Where is Jastec located?

Jastec is listed at Jastec B/D 2F, 92-7 Kumgok-dong, Boondang-gu, KR 463-804 in the IEEE OUI registry entry for 4C:8F:A5. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does Jastec own?

Jastec holds 2 OUI prefixes in the IEEE registry, of which 4C:8F:A5 is one. A device made by Jastec could carry a MAC address from any of them.

Jastec

MAC address prefix 4C:8F:A5 is registered to Jastec in the IEEE OUI registry. Any device whose MAC address begins with 4C:8F:A5 has a network interface built by Jastec. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address — it covers every MAC from 4C:8F:A5:00:00:00 to 4C:8F:A5:FF:FF:FF.

OUI prefix: 4C:8F:A5
Hyphen form: 4C-8F-A5
MAC range: 4C:8F:A5:00:00:00 – 4C:8F:A5:FF:FF:FF
Addresses in block: 16,777,216
Organization: Jastec
Address: Jastec B/D 2F, 92-7 Kumgok-dong, Boondang-gu, KR 463-804
Source: IEEE OUI registry

Have a full MAC address? Look it up— we'll also tell you if it's a randomized (private) address rather than a real manufacturer prefix.

Other prefixes from Jastec

Jastec holds 2 OUI prefixes in total. A device with this exact prefix could just as well carry any of these:

00:1F:09

Assignment history (2)

The IEEE registry publishes current state only — this is the change record we've kept since we started tracking it daily.

2016-07-29Assigned to "Jastec"
archived source →
2026-07-17Assigned to "Jastec"

Nearby in the registry

The prefixes assigned immediately before and after 4C:8F:A5:

FAQ

Which company owns MAC address prefix 4C:8F:A5?: MAC address prefix 4C:8F:A5 is registered to Jastec in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 4C:8F:A5 has a network interface built by Jastec.
What is the OUI 4C:8F:A5?: 4C:8F:A5 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Jastec. It covers every address from 4C:8F:A5:00:00:00 to 4C:8F:A5:FF:FF:FF, or 16,777,216 addresses in total. It is also written 4C-8F-A5.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 4C:8F:A5:00:00:00 that is 4C:8F:A5 — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.
Where is Jastec located?: Jastec is listed at Jastec B/D 2F, 92-7 Kumgok-dong, Boondang-gu, KR 463-804 in the IEEE OUI registry entry for 4C:8F:A5. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does Jastec own?: Jastec holds 2 OUI prefixes in the IEEE registry, of which 4C:8F:A5 is one. A device made by Jastec could carry a MAC address from any of them.